Power Factor Control with a Battery Energy Storage System (BESS)

Power Factor Control with a Battery Energy Storage System (BESS)

This report explores reactive power, power factor, and the ability of the Australian Energy Storage Knowledge Bank's Mobile Test Platform to control these quantities. Reactive power provides no useable power, but increases the load on the power system and reduces the amount of real, useful power that can be delivered. These concepts are explored with the aid of the power triangle, P-Q unit circle, and real waveforms.

Power factor control and P-Q circle operation in Thebarton 2017
Power factor control and P-Q circle test data from Thebarton. Includes inverter and generation bus total power quality data aggregated every 3 seconds.
CASE STUDY 2: Power Factor Control with a BESS
In an electrical power system, power is the amount of energy that flows over a period time. For direct current (DC) power systems, where the voltage and current remain relatively constant for small periods of time, the power is simply voltage multiplied by current. For an alternating current (AC) power system, the voltage and current cycle between positive and negative values. Real and useful power (active power) is only transferred when the voltage and current waveforms overlap. The ideal case (all power is useful) occurs when the voltage and current waveforms have the same shape and are perfectly aligned (are in-phase). In this ideal case, the power can also be calculated as voltage multiplied by current.
Waveform when reactive power increased during P-Q circle operation in Thebarton 2017
Raw, high bandwidth waveform recorded when the inverter's reactive power setpoint is increased. The waveform is 3 seconds in length, containg 1.5 million samples per inverter channel, 300 thousand samples per channel for other electrical channels, and 3 samples per temperature/weather channel.
Waveform for idle inverter before P-Q circle operation in Thebarton 2017
Raw, high bandwidth waveform recorded when the inverter was connected to the grid, and left idle. Also captures inrush current during connection. The waveform is 4 seconds in length, containg 2 million samples per inverter channel, 400 thousand samples per channel for other electrical channels, and 4 samples per temperature/weather channel.